A TrackTalk banner ad says "Behold the biggest, boldest box ever. Record 1,000 hours, 4 channels at once. The NEW TiVo Premiere XL4 DVR". What are they talking about? I thought the XL4 had 300 hours of capacity.

The XL4 can only record digital cable, so unlike the 2 tuner unit there is no quality selection for SD. On the 2 tuner unit they're quoting SD hours in the Basic quality from an analog station, which is only about 800MB per hour. Most digital cable channels are closer to 2-3GB per hour. So the 1,000 hour figure is about right for digital SD.

Dan203 is correct. However, it is worth noting that you could get upwards of 750 hours HD if Comcast ever gets in the MPEG-4 game, as they will probably compress the sh*t out of it like they do now. Even Comcast's MPEG-2 HD bumps the hour capacity of the XL4 up quite a bit. I guess it's one upside to compressing the sh*t out of everything and having intermittent macro blocking and artificating issues due to compression.